Head rest

Abstract

A headrest is provided including a movable unit that can be shifted to multiple positions in the front-rear direction in a normal mode. A headrest includes first and second headrest pillars, a stationary unit disposed between the first and second headrest pillars, a movable unit movable apart from or close to the stationary unit toward a front or rear direction, an X linkage connecting the stationary unit to the movable unit and including an inside linkage segment and an outside linkage segment rotatably connected each other at a central connecting intersection, and a front-rear locking mechanism including a lock receiver and a locking component engageable with the lock receiver, to lock or unlock the movable unit movable relative to the stationary unit toward the front or rear direction.

The invention claimed is: 
     
       1. A headrest comprising:
 first and second headrest pillars; 
 a stationary unit disposed between the first and second headrest pillars; 
 a movable unit movable apart from or close to the stationary unit toward a front or rear direction; 
 an X linkage connecting the stationary unit to the movable unit, the X linkage including an inside linkage segment and an outside linkage segment rotatably connected each other at a central connecting intersection; and 
 a front-rear locking mechanism comprising at least one lock receiver and at least one locking component engageable with the lock receiver, the locking mechanism being configured to lock or unlock the movable unit movable relative to the stationary unit toward the front or rear direction, wherein 
 the stationary unit has at least one clearance to receive that at least one lock receiver, and 
 the at least one lock receiver protrudes rearward from the stationary unit through the clearance in response to the movement of the movable unit toward the rear direction. 
 
     
     
       2. The headrest according to  claim 1 , wherein the outside linkage segment and the lock receiver are integrated with each other. 
     
     
       3. The headrest according to  claim 1 , wherein the inside linkage segment and the lock receiver are integrated with each other. 
     
     
       4. The headrest according to  claim 1 , wherein the lock receiver includes a ratchet mechanism having a plurality of teeth arranged on an arc line corresponding to rotation of the X linkage. 
     
     
       5. The headrest according to  claim 1 , wherein the lock receiver is disposed in the center between the first and second headrest pillars. 
     
     
       6. The headrest according to  claim 1 , wherein the lock receiver is disposed in a right or left portion relative to the center between the first and second headrest pillars. 
     
     
       7. The headrest according to  claim 1 , wherein the at least one lock receiver includes a plurality of lock receivers disposed in right and left portions relative to the center between the first and second headrest pillars. 
     
     
       8. The headrest according to  claim 7 , wherein the lock receivers are disposed in right and left spaces, the right and left spaces being defined by the stationary unit and the X linkage in a width direction of the headrest. 
     
     
       9. The headrest according to  claim 7 , further comprising an operation unit to operate the at least one locking component, wherein
 the at least one locking component includes a plurality of locking components corresponding to the lock receivers, and 
 the operation unit simultaneously operates the locking components. 
 
     
     
       10. The headrest according to  claim 7 , further comprising an operation unit to operate the at least one locking component, wherein
 the at least one locking component includes a plurality of locking components corresponding to the lock receivers, the locking components being coupled to each other with a coupler such that the locking components move in synchronization.